This is the third book in Miguel Aviles Zerkian Chronicles, which started with Prince Zeethar’s Defection and continued through Ambush on Pluto and now the present volume. They are narrated by the aforementioned Zeethar, a member of the Zerkian race intent on invading Earth but having lived disguised as a human for a decade (the Zerkians have shape-changing capabilities). His impersonation of an Earthman is, somewhat surprisingly, not the central focus of the first story. Rather, it involves a number of betrayals by other Zerkians that have the effect, along with the human emotions he has picked up (including loving his human wife), place him on Earth’s side.

The second book starts two years later, with the initial Zerkian invasion repulsed with the help of some alien allies. Now the human-alien coalition is working on a weapon to end the war, the research being done on Pluto. But the Zerkians strike there first, leaving Zeethar in a race to determine who will recover the weapon research first.

Now, in Retaliation, Zeethar is returning to his adopted home, Earth, and wife, Starlette, only to find that the planet has been occupied by the Zerkians in his absence. Zeethar ends up as a prisoner, with an old enemy from his original home on his way to oversee his execution.

The rest of the book is filled with hair-breath escapes, space battles, and the discovery of yet another unlikely race of allies, this time from another dimension. But don’t expect the book to wrap up everything. In fact, the ending demands more novels in the series. We may not learn in this book the ultimate outcome of the battle between the humans and Zerkians, but just getting there is half the fun. — Paul Dellinger